Means to reduce piglet stress caused by tail docking
Take Home Message: Stress due to tail docking in piglets is reduced by using a hot iron compared with blunt cutting.
Tail docking using a heated cautery iron may reduce the acute physiological stress
response caused by tail docking as compared with conventional tail docking using blunt trauma cutting. Just one of the findings of study, led by Mhairi Sutherland at the Texas Tech University, to determine the stress responses to tail docking in piglets and to compare two methods of tail docking; cautery iron (CAUT) and the more commonly used blunt trauma cutters (BT).
“Behaviour appeared to be similar between piglets tail docked using CAUT and BT cutting after tail docking. But cortisol concentrations were lower in CAUT piglets compared to levels in piglets docked using BT cutting at 60 minutes post tail docking,” she said.
Tail docking is a routine management practice carried out on pig farms to control tail biting. Analgesics and anaesthetics are not routinely used for pain relief for tail docking on commercial pig farms in the US.
“Therefore, it would be beneficial to the welfare of piglets to determine other methods of tail docking that may reduce the acute stress caused by this procedure,” she said, explaining the rationale behind her team’s work.
At approximately six days of age, piglets were tail docked using CAUT (n520), BT (n520) or sham tail docked with their tails remaining intact (CON; n540). Blood samples were taken prior to tail docking and at 30, 60 and 90 min after tail docking to evaluate the effect of tail docking on white blood cell (WBC) measures and cortisol concentrations.
This experiment was repeated to observe behaviour without the periodic blood sampling, so as not to confound the effects of blood sampling on piglet behaviour. Piglet behaviour was recorded in the farrowing crate using one-minute scan-samples via live observations for 60 minutes prior to and 90 minutes after tail docking.
“And we found that total WBC counts were reduced among BT and CAUT compared with CON piglets 30 minutes after tail docking. Cortisol concentrations were higher among BT compared with CON and CAUT piglets 60 minutes after tail docking. And cautery and BT-docked piglets spent more time posterior scooting compared with CON piglets between zero and 15 minutes, and 31 and 45 minutes after tail docking,” said Dr Sutherland.
The team also found that piglets tail docked using CAUT and BT tended to spend more time sitting than CON piglets between zero and 15 minutes post tail docking.
“So elevated blood cortisol can be reduced by the use of the CAUT rather than the BT method of tail docking. And although the tail docking-induced rise in cortisol was prevented by using CAUT, the behavioural response to BT and CAUT docking methods was similar.
“Further studies are needed to confirm these findings and to determine the possible chronic stress caused by tail docking in piglets,” she added.
Full details: Sutherland MA, Bryer PJ, Krebs N and McGlone JJ: “Tail docking in pigs: acute physiological and behavioural responses.” Animal 2: 292-297.
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